Treatment Database

A synthetic mineralocorticoid that expands blood volume by increasing sodium and water retention in the kidneys. It is used off-label for POTS and other forms of orthostatic intolerance to reduce dizziness, lightheadedness and tachycardia on standing. Evidence in POTS is limited to small uncontrolled studies, such as a 2000 study of 11 women whose symptoms improved on bisoprolol, fludrocortisone or both (Clinical Autonomic Research). The 2015 Heart Rhythm Society expert consensus lists it as an option for increasing blood volume, and a 2025 systematic review of POTS trials notes that current guidelines rest on weak evidence and clinical expertise. In ME/CFS with neurally mediated hypotension, a randomized controlled trial (Rowe et al., JAMA 2001; n=100, 9 weeks) found no benefit: 14% improved on fludrocortisone vs. 10% on placebo, with more dropouts on the drug (26% vs. 16%). Because it causes sodium retention and potassium loss, regular blood pressure and electrolyte checks are recommended, and potassium supplementation may be needed.